I recently had Pergo plank flooring installed throughout the house. About two to three weeks after the professional install (an experienced private contractor), the plank flooring in the hallway, right at the bedroom door threshhold began to rise

. There are three 5 inch planks involved.the two outside rising at small angles and the third in the center flat. The total rise is about 1/4 inch. When weight is placed on it it will lie flat. I & the contractor pulled the baseboards to check spacing. There is more than adequate space at the walls. We removed all of the furniture from the bedroom to fully unweight the floor and using a pry bar attemted to move the floor inside the bedroom (this floor is level and the pergo flat from the threshhold to the far wall). No movement.
He says he has not seen this problem before. usually a bubble, even a small one indicates there is not space for the floor to float. Based on the inspection of the gaps under the baseboards it should float - but it does not?
Possible solutions suggested by him in the order of his preference are 1. remove the flooring to the place where it is binding and replace the boards that are making the rise (theory being there is a problem with one or more boards connection joints), 2. top nail the rise down - which he states may work for the life of the floor or for a brief period only (no way to know for sure), or put in a transition at the door to give the risng floor room to move (my wife really hates this idea).
I am at a loss. It seems the floor should float one way or the other, yet it is fine on either side of the three boards. Would greatly appreciate any ideas to solve this problem. Help!:001_unsure: